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PHP Array array_fill_keys() Function (With Examples)

In this tutorial, we will learn about the PHP array_fill_keys() function with its usage, syntax, parameters, return value, and examples. By IncludeHelp Last updated : December 31, 2023

PHP array_fill_keys() Function

The array_fill_keys() function is used to fill a given array with a value where keys are specified. We will use an array that contains keys, all these keys will be filled with the value and return a new array.

Syntax

The syntax of the array_fill_keys() function:

array_fill_keys(keys, value) : array

Parameters

The parameters of the array_fill_keys() function:

keys is an array and its value will be used as keys for the new array.
value to be filled for the keys.

Return Value

The return type of this method is array, it returns the filled array.

Sample Input/Output

Input:
$keys = array("Name", "Age", "Gender", "Address"); 
value = "N/A"

Function call:
array_fill_keys($keys, "N/A");
Output:
Array
(
    [Name] => N/A
    [Age] => N/A
    [Gender] => N/A
    [Address] => N/A
)

PHP array_fill_keys() Function Example

<?php
//keys (creating array)
$keys = array("Name", "Age", "Gender", "Address");

//creating an array with these keys
//and, filling all keys with default value
$arr = array_fill_keys($keys, "N/A");

print_r ($arr);
?>

Output

The output of the above example is:

Array
(
    [Name] => N/A
    [Age] => N/A
    [Gender] => N/A
    [Address] => N/A
)

To understand the above example, you should have the basic knowledge of the following PHP topics:

PHP array_fill() Function

PHP array_filter() Function